Method for insolubilizing vegetable seed globulin and phospho-protein artificial filamentary products



1951 w. E. TETLOW EIAL 2,565,935

, METHOD FOR INSOLUBILIZING VEGETABLE SEED GLOBULIN AND PHOSPHO-PROTEIN ARTIFICIAL FILAMENTARY PRODUCTS Filed May 23, 1949 Inventors WILLIAM EDWARD TETLOW ROBIN H. K. THOMSON M1 torneys Patented Aug. 28, 1951 .METHOD FOR INSOLUBILIZING VEGETABLE SEED GLOBULIN AND PHOSPHO-PROTEIN ARTIFICIAL FILAMENTARY PRODUCTS William E. 'I'etlow, Saltcoats, and Robin H. K.

Thomson, Fairlie, Scotland, assignors to Imperial Chemical Industries Limited, a corporation of Great Britain Application May 23, 1949, Serial No. 94,896 In Great Britain May 28, 1948 Claims. 1

The present invention relates to a new or improved method for insolubilising artificial filaments, threads, fibres and the like filamentary products spun from protein solutions, and more particularly those obtained by the spinning of solutions of vegetable seed globulins, for instance peanut protein, or phospho-proteins, for instance casein, in aqueous alkaline or other suitable aqueous solvent media into suitable acidified saline coagulating baths. Sodium sulphate solutions slightly acidified with sulphuric acid are in practice most advantageously used as the coagulating baths.

In British Patent Specification No. 597,497 there is described and claimed inter alia a method of insolubilising artificial filamentary products obtained by the spinning of solutions of vegetable seed globulins, for instance peanut proteins; or phospho-proteins, for instance casein, in aqueous alkaline or other aqueous solvent media into suitable acidified saline coagulating baths which comprises treating the said filamentary products in an aqueous formaldehyde bath saturated to both sodium chloride and sodium sulphate or to both' sodium chloride and magnesium sulphate at a pH of 4 to 6 and at a temperature not exceeding 60 C. and thereafter treating the filamentary products in an aqueous formaldehyde bath strongly acidified with sulphuric acid and saturated with sodium sulphate or magnesium sulphate at the temperature employed, the said strongly acidified formaldehyde bath being at a raised temperature.

It is stated therein that if the formaldehyde bath of pH 4 to 6 is saturated to both sodium chloride and sodium sulphate then the strongly acidified formaldehyde bath is preferably saturated with sodium sulphate, while if the formaldehyde bath of pH 4 to 6 is saturated to both sodium chloride and magnesium sulphate then the strongly acidified formaldehyde bath is preferably saturated with magnesium sulphate.

It is also stated therein that if the temperature of the first bath is 50 C. a period of about five minutes is suflicient, and that if the temperature is about 40 C. 8 minutes to minutes are required. It is also stated that if the temperature of the second bath is about 70 C. the time required for treatment is usually about 10 to 15 minutes.

It is also stated therein that the coagulated filaments are first passed through a saturated sodium chloride bath at approximately C. in which they remain until their longitudinal contractility has been greatly reduced. It is filato give a saturated solution thereof; that the sodium sulphate may be omitted or that the sodium sulphate content may be low; and that the temperature may be as high as 80 C. and preferably between 25 and 80 C. It has also been found that the second bath 1. e. the aqueous formaldehyde bath strongly acidified with sulphuric acid and saturated with sodium sulphate, should preferably contain sodium chloride and that temperatures higher than 90 C. can be used though preferably the temperature is between and 98 C.

The changes which can thus be effected in the composition of the said first bath permit baths to be made which are of less specific gravity than the specific gravity of the protein fibres. This is extremely useful as it is very desirable that where the insolubilisation is carried out by immersion in successive treating liquids for as many as possible-of these to have a specific gravity lower than that of the protein filamentary products. Particularly is this so if the insolubilisation is to be carried out under non-tensioning conditions on a continuous travelling tow of protein filaments.

According to the present invention the method of insolubilising artificial filamentary products obtained by the spinning of solutions of vegetable seed globulins, for instance peanut proteins, or phospho-proteins, for instance, casein, in aqueous alkaline or other aqueous solvent media into suitable acidified saline coagulating baths comprises subsequently to the treatment of the filamentary products formed on coagulation in a relaxing solution, treating the thus relaxed filamentary products in an aqueous formaldehyde solution containing not less than 240 grams sodium chloride per litre of solution, having a pH value between 4 and 7, and at a temperature not exceeding C. and preferably at a temperature of 25 to 80 C. and subsequently treating the filamentary products in a strongly acidified aqueous formaldehyde solution containing per litre 3 of solution between 250 and 325 grams sulphuric acid, between 370 and 480 grams of sodium sulphate and preferably between 30 and 130 grams sodium chloride, the said strongly acidified formaldehyde solution being at a raised temperature, preferably at a temperature of 70 to 98 C.

Preferably the relaxing solution according to the present invention is also one containing not less than 240 grams sodium chloride per litre of solution, and having a pH value of between 4 and '7. The said relaxing solution however is free from formaldehyde and is at a temperature of to 40 C., and preferably at a temperature of to 25 C.

In accordance with one embodiment of the present invention. the method particularly adapted for the insolubilising under non-tensioning conditions a continuous travelling tow of artificial filamentary products obtained by the spinning of solutions of vegetable seed globulins, for instance peanut proteins, or phospho-proteins, for instance casein, in aqueous alkaline or other aqueous solvent media into suitable acidified saline coagulating baths comprises immersing the tow formed on coagulation in two liquids each containing per litre of solution between 240 and 320 grams of sodium chloride, less than 60 grams sodium sulphate and less than 3 grams of sulphuric acid, the first of these two liquids being substantially free from formaldehyde and at a temperature of 10 to 40 0., preferably at a temperature of 15 to 25 C., and the second of these two liquids having between 10 and grams formaldehyde and being at a temperature not exceeding 80 0;, and preferably at a temperature of to 80 C., and subsequently treating the tow in a third liquid containing per litre of solution between and 130 grams of sodium chloride, between 3'70 and 500 grams of sodium sulphate, between 250 and 325 grams of sulphuric acid and between 10 and 20 grams of formaldehyde and being at a raised temperature, preferably at a temperature between 70 and 98 C.

The invention is further illustrated by the following example in which the parts are parts by weight except where otherwise indicated and with reference to the accompanying diagrammatic drawing.

A solution of ground nut globulin containing 20% globulin, 1.1% sodium hydroxide and 78.9% water is extruded through a spinneret I into a coagulating bath 2 containing 300 gm./l. sodium sulphate and 50 gm./l. sulphuric acid. The coagulated tow 3 is stretched between godets I, 5 and then treated for 3 minutes with a solution containing 290 gm./l. sodium chloride, 30 gm./l. sodium sulphate, 0.5 gm./l. sulphuric acid at 20 C. contained in the trough of a ring trough 1 according to the method claimed in copending application Serial No. 2,246, filed January 14, 1948, now U. S. Patent 2,555,065. This treatment is effected by leading the tow 3 under tension to a godet 8 situated vertically above the centre line of the trough of the ring-trough I through a reciprocating spacing device 8 at least 3 feet above the surface of the liquor in the trough and so into the trough in which the fibre is deposited steel, fitted with an adjustable weir so that the height of liquor in the trough may be varied at will. The tow 3 sinks on to the base 9 of the trough i and is carried around with the trough I which revolves once in 3 minutes. The tow 3 is taken up not less than 3 inches from the fibre inlet and is then mangled between squeeze rolls H after which it is stretched between two godets l2 and [3.

The tow is now treated for 3 minutes in a solution containing 300 gm./l. sodium chloride, 24 gm./l. sodium sulphate, 1 gm./l. sulphuric acid and 15 gm./l. formaldehyde at 55 C. contained in the trough of a ring trough l6 similar to ring trough 1 and again according to the method claimed in co-pending application Serial No. 2,246, filed January 14, 1948, now U. S. Patent 2,555,065. This operation is effected by passing the tow 3 from a godet i4 situated vertically above the centre line of the trough of said ring trough l6 through a reciprocating spacing device l5. The tow 3 after leaving the trough of the ring trough I6 is mangled between squeeze rolls IT and passed from a godet l8 placed vertically above the centre line of the entry i9 of a vertically positioned helical coil 20 of length 150 feet and diameter 4 feet through which flows a treating liquor consisting of 75 g1n./l. sodium chloride, 420 gm./l. sodium sulphate, 300 gm./l. sulphuric acid and 12 gm./l. formaldehyde at C. The time Of passage of the tow through this coil 20 is 70 seconds. On leaving the outlet of the coil 20 the tow 3 is taken up from a godet 2| and washed and dried by any known method.

We claim:

1. A method of insolubilizing artificial filamentary products obtained by spinning aqueous alkaline solutions of proteins selected from the group consisting of vegetable seed globulins and phopho-proteins into acidified saline coagulating baths which comprises first relaxing the filamentary products by impregnating the same with an aqueous solution containing not less than 240 grams of sodium chloride per litre of solution and having a pH of between 4 and 7, and being substantially free of formaldehyde, thereafter impregnating the thus treated filamentary products at,a temperature not exceeding 80 C. with an aqueous formaldehyde solution containing not less than 240 grams of sodium chloride per litre and having a pH of between 4 and 7 and thereafter impregnating the filamentary products at a temperature between 70 and 98 C. in a strongly acidified, aqueous formaldehyde solution containing, per litre of solution, between 250 and 325 grams of sulphuric acid and between 370 and 480 grams of sodium sulphate.

2. The method of claim 1 wherein the said strongly acidified aqueous formaldehyde solution contains between 30 and grams sodium chloride.

3. The method of claim 1 wherein the aqueous formaldehyde solution having a pH value between 4 and '7 is at a temperature of between 25 C. and 80 C.

4. The method of claim 1 wherein the relaxing solution is at a temperature of 10 C. to 40 C.

5. The method of claim 4 wherein the temperature of the relaxing solution is between 15 and 20 C.

6. The method of claim 1 wherein said protein is peanut protein.

7. The method of claim 1 wherein said fila mentary products are treated in an untensioned condition.

8. The method 01' claim 1 wherein the filamentary products are in the form of a continuous tow and said tow is treated in an untensioned condition.

9. Insolubilised artificial filamentary products of vegetabl seed globulins and phospho-proteins produced by the method claimed in claim 1.

10. A method of insolubilizing artificial filamentary products obtained by spinning aqueous. alkaline solutions of proteins selected from the group consisting of vegetable seed globulins and phospho-proteinsinto acidified saline coagulating baths which comprises impregnating the coagulated filamentary products at a temperature of 10 C. to 40 C. in a relaxing solution containm per liter of solution, between 240 and 320 grams of sodium sulphate and less than 3 grams of sulphuric acid, said relaxing solution being substantially free or formaldehyde, thereafter impregnating the thus relaxed filamentary products at a temperature not exceeding 80' C. in an aqueous formaldehyde solution containing, per liter of solution, between 240 and 320 grams of sodium chloride, less than 60 grams of sodium sulphate, less than 3 grams of sulphuric acid and between 10 and 20 grams of formaldehyde, the pH of said aqueous formaldehyde solution being between 4 and 7, and subsequently impregnating the filamentary products at a temperature beformaldehyde.

WILLIAM E. 'I'ETLOW. ROBIN H. K. THOMSON.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Country Date Great Britain Jan. 27, 1948 Number 

1. A METHOD OF INSOLUBILIZING ARTIFICIAL FILAMENTARY PRODUCTS OBTAINED BY SPINNING AQUEOUS ALKALINE SOLUTIONS OF PROTEINS SELECTED FROM THE GROUP CONSISTING OF VEGETABLE SEED GLOBULINS AND PHOPHO-PROTEINS INTO ACIDIFIED SALINE COAGULATING BATHS WHICH COMPRISES FIRST RELAXING THE FILAMENTARY PRODUCTS BY IMPREGNATING THE SAME WITH AN AQUEOUS SOLUTION CONTAINING NOT LESS THAN 240 GRAMS OF SODIUM CHLORIDE PER LITRE OF SOLUTION AND HAVING A PH OF BETWEEN 4 AND 7, AND BEING SUBSTANTIALLY FREE OF FORMALDEHYDE, THEREAFTER IMPREGNATING THE THUS TREATED FILAMENTARY PRODUCTS AT A TEMPERATURE NOT EXCEEDING 80* C. WITH AN AQUEOUS FORMALDEHYDE SOLUTION CONTAINING NOT LESS THAN 240 GRAMS OF SODIUM CHLORIDE PER LITRE AND HAVING A PH OF BETWEEN 4 AND 7 AND THEREAFTER IMPREGNATING THE FILAMENTARY PRODUCTS AT A TEMPERATURE BETWEEN 70* AND 98* C. IN A STRONGLY ACIDIFIED, AQUEOUS FORMALDEHYDE SOLUTION CONTAINING, PER LITRE OF SOLUTION, BETWEEN 250 AND 325 GRAMS OF-SULPHURIC ACID AND BETWEEN 370 AND 480 GRAMS OF SODIUM SULPHATE. 